1. Field of the Invention
The present invention relates to an electrophotographic apparatus capable of superposed image recording.
2. Description of the Prior Art
Image synthesis in copying has for example been achieved by synthesizing images on an original document and copying thus synthesized original on a copying machine. There is however involved a cumbersome procedure of adhering an original to be synthesized to another original with a transparent adhesive tape, and the obtained original document is often smeared by the use of such adhesive tape.
Apart from such manual image synthesis, automatic image synthesis has been proposed with a copying machine with intelligent functions, but such apparatus is inevitably complex and expensive. It is also possible to effect such image synthesis by forming an electrostatic latent image of a first original image on a photosensitive member, then erasing an unnecessary part of said latent image by selective on-off control of erasing lamps consisting for example of an LED array, then developing and transferring said image through a known electrophotographic process to obtain a partially lacking copy image, then forming another latent image with inverted on-off control of the erasing lamps so that it can be fitted into the lacking portion of the above-mentioned image, and rendering said latent image visible to obtain a synthesized copy image.
However, in the transfer of the developed image from the photosensitive member to the copy sheet, there may result an error in the registration between the front end of the image and that of the copy sheet, and there may also result a shrinkage or elongation of the copy sheet by heat and pressure when it passes the fixing device.
Consequently the above-mentioned image synthesis with inverted on-off control of the erasing lamps frequently results in overlapping boundaries of two images, thus giving rise to synthesized images lacking aesthetic appeal.